I am having a peculiar problem with Photoshop 2020 CC lately. When I open multiple files as layers from Lightroom, not all of the images open as layers in one file. Usually, one layer gets opened as a separate file. Sometimes, the process stops in the middle of the process, opening a few layers, and one images as a separate file, but not loading all layers. Also, I have the impression that this process is slower than it should be loading the images as well, regardless of whether it loads them all as layers in one file. When I reset preference file in PS, the problem is solved, but it comes right back very quickly.
I am using the current CC versions of Lightroom and Photoshop. I have very occasionally had this problem in the past year or so, but now it is happening all the time.
Another problem I am having, and I don't know whether it is related, is that saving Tiff files from Photoshop seems to be quite slow, even for flattened files.